Floor height gauge



FIG. 1 is a perspective view of the front and the top of the floor height gauge according to my new design;

FIG. 2 is a perspective view of the front and the bottom thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The dashed lines shown in the drawings illustrate environmental structure and form no part of the claimed design. 

CLAIM The ornamental design for floor height gauge, as shown and described. 